You know what breaks, in human beings' experiences?

Everything. All the time.

So the holier-than-thou, thou-shall-not-deploy-less-than-perfect perspective is pretty irrelevant.

This is a side project. That did something neat. The author should be commended, not lambasted for not rebuilding Gmail on their own.

And God knows the Internet would be a better place with a little more weirdness again.

I dont think they are being lambasted, they should just put a warning on their site. Email is a very messed up ecosystem, and people who use email don't understand that. This is very cool, there should just be a disclaimer that this is a side project and will break often. Email is notoriously a pain in the ass if it's a full time job, much less a side project that's losing money. He's not selling this to quirky techies, his primary advertisement was tic tok. That's kind of irresponsible to not warn people this should just be for fun.

You're not wrong per se, but rather: there should just be a disclaimer on Email that this is a very messed up ecosystem and will break often. It's not specific to xn--ds8h.kz et al.

How do you pay your taxes with email?

They probaly means we use that email address when paying taxes so notification/receipt etc will be send to that email address.